A conventional stator yoke for an axial gap coreless motor is made of a magnetic material such as a single sheet of silicon steel sheet or thin sheet of silicon iron as disclosed, for example, in JP H05-227717 A.
When strong magnets such as a sintered neodymium magnet are employed as a rotor magnet in a motor configured by a stator yoke made of a single sheet of silicon steel, the magnetic attraction of the rotor magnet may cause stator vibration and noise resulting in degradation in motor stop precision. The magnetic attraction may also cause magnetic flux saturation inside the stator yoke leading to invalid torque.